If you have an alternative means to phone in, you could try the random lottery of the VM customer support by phone. At least you now know the reason for no phone.
If you changed your package as part of the move to the hub 4, you could also log into 'My Virgin Media' and double check that you still have the landline service showing as part of your package. There have been some odd, one-off topics in the past on here where certain services have been dropped during package changes (unbeknown to the customer). Unlikely that is so but you could double check.
The VM forum team will reply here in due course (normally within a day or two but not sure on current timings with BH w/e etc.) and they will assist you.
I'm sorry to hear you're experiencing landline issues and that you did not receive the help you require via phone, that's not the high standard of service we aim to provide. I apologise.
I would like to take a look at your account, run some diagnostics and see if we need to book an engineer visit. I shall send you a private message now to obtain the details required. Please look out for the purple envelope in the top right corner and get back to me when you can.